This invention relates to an electric toy train track that has a rail that delivers electric current to a train that runs on the track.
Conventional "O" gauge type track comprises three parallel metal rails that are joined in laterally spaced apart relation to each other by means of metal cross ties. The center rail is the "hot" rail that carries electric current to the train.
In order to avoid potential short circuiting of the electric current through a cross tie, it is necessary that a non-metallic insulator be placed in the joint between each cross tie and the center power rail for the purpose of electrically insulating the center power rail from the cross tie. These insulators are small, loose pieces that are placed between the cross tie and the center rail prior to their being joined. Joining is performed by placing the center rail onto a cross tie so that the base of the rail rests on an intervening insulator; then, tabs of the cross tie adjacent the sides of the rail's base are clinched and crimped against the base, mechanically joining the cross tie and the rail while causing the insulator to wrap around the sides and top of the base and become entrapped in the joint.
That method for fabricating tracks involves a considerable amount of manual labor, especially in placement of the insulators onto the cross ties. The width of an insulator is just large enough to fully span the width of the cross tie's top platform surface against which the base of the rail is disposed sandwiching the insulator in-between. Improper placement of an insulator can give rise to the potential for shorting of the power rail to the cross tie thereby shorting electrical current from the toy train.
Thus, during fabrication of the track, extreme care must be taken both in placement of the insulators between the power rail and the cross ties and also in the joining procedure to make sure that the insulation is ultimately in the proper place. Since this prior procedure uses manual labor, the possibility that defective parts will be produced is real. If these defective parts are caught before they reach the consumer, that is one thing, but if they reach the consumer, they can lead to disappointment and frustration for what is intended to be a pleasurable and enjoyable hobby, especially for young people.
The need for placing a small insulator piece between the power rail and each cross tie is a further disadvantage because it renders the fabrication poorly suited for automated assembly operations which otherwise could improve the efficiency of mass-producing the track.
The present invention is directed to a new and improved toy train track of the aforedescribed type which eliminates these small insulator pieces and the attendant criticality in their placement between the power rail and the cross ties. Moreover, the invention has the advantage of providing insulation throughout the entire length of the power rail, not just at each cross tie.
The invention is practiced, in the preferred embodiment, by extruding an inexpensive non-metallic electric insulating material, PVC plastic for example, onto the metal piece that forms the structure of the power rail. The rail is formed from a flat metal strip by conventional forming procedures (i.e. roll-forming) to produce the desired cross sectional shape for the rail. In this cross sectional shape, the extruded electric insulating material covers the bottom of the base of the rail, the sides of the base, and portions of the top of the base immediately contiguous the sides, and the insulation is continuous throughout the length of the rail.
When the rail is assembled to cross ties to form the track, the rail's base is simply placed against the cross ties' top platform surfaces, and then the adjacent tabs of the cross ties are clinched and crimped against the base thereby securely joining the two parts in an insulated manner so that there is no electrical conductivity between them. In this way, the power rail is insulated from the cross ties by a procedure that is not dependent upon the manual placement of small individual insulator pieces between the cross ties and the power rail. Advantages are that the assembly is well-suited for automated fabrication because the small insulator pieces are eliminated, and that the potential for defective parts due to improperly placed insulators is minimized.
The foregoing features, advantages and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment according to the best mode contemplated at the present time in carrying out the invention.